1. Field of the Invention
The present invention relates to a waterproof structure for a charging connector and, in particular, to a waterproof structure for a charging connector which is used in an apparatus such as an electric car requiring a charging operation.
2. Description of the Prior Art
Conventionally, in carrying cars used in physical distribution and the like, as well as in electric cars which have attracted public attention in recent years, there is provided in a suitable portion of the car body thereof a charging connector which is a connecting means for charging. Such a charging connector includes a waterproof cap which prevents the entrance of water or dust when not in use so as to prevent generation of a leak or the like. Also, to prevent the charging connector from projecting out from the vehicle body, there is employed a structure in which the charging connector is disposed in a recessed portion of the vehicle body.
Especially, in a waterproof structure for a charging connector when the charging connector is used outdoors (for example, in an electric car or the like), because there is a high possibility that water can enter, a body cover (a cover which forms the outer surface of the car body and can be freely opened and closed) provided on the car body surface side can be used to prevent entrance of water and dust to some degree. There is also provided a waterproof cap in the connecting opening of the charging connector, thereby providing a double waterproof and dustproof structure.
In this type of waterproof structure for a charging connector, for example, as shown in FIG. 7, a waterproof cap 2 is connected to charging connector 1 by means of a chain 3. When not in use (when a charging operation is not preformed), a user fits the waterproof cap 2 into the connecting opening of the charging connector 1, thereby preventing entrance of water and dust. The charging connector 1 is conveniently disposed within a recessed portion 8 and the opening of the recessed portion 8 can be opened and closed by use of a body cover 7. In a different example of the conventional waterproof structure, as shown in FIG. 8, the waterproof cap 2 is arranged such that it can be swung, by means of a pin 4, around a bracket 6 provided in the side portion of the connecting opening of the charging connector 1. Further, for example, one end of a torsion spring 5 wound around the pin 4 is engaged with the bracket 6, and the other end thereof is engaged with the waterproof cap 2. The waterproof cap 2 can be always closed by the force of the torsion spring when a charging operation is not performed. In addition, the cover is closed by the body cover 7.
If the body cover 7 is inadvertently left open, this can be immediately discovered by an operator. Therefore it is unlikely that the operator will forget to close the body cover. However, especially in the structure shown in FIG. 7, if the body cover 7 is closed when the waterproof cap 2 for closing the opening of the charging connector 1 is forgotten to be closed, then the connector is not sealed in a waterproof manner. That is, rainwater and dust can enter the charging connector 1, which results in the failure of the charging connector 1. In this case, to prevent the failure to close the waterproof cap 2, for example, the chain 3 may be extended such that, when the waterproof cap 2 is removed, the cap 2 can be moved out of the recessed portion. In this structure, when the operator tries to close the body cover 7 without closing the waterproof cap 2, then the chain 3 or waterproof cap 2 will be nipped by the body cover 7, which tells the operator that the operator has forgotten to close the waterproof cap 2.
However, even the above-mentioned structure still has a drawback that it requires a troublesome operation to push the excessive portion of the chain into the interiors of the body cover 7. That is, in this structure, even when the waterproof cap 2 is incompletely closed, if the body cover 7 is closed, then it is impossible to confirm the incompletely closed condition of the waterproof cap 2 from the outside.
Also, as shown in FIG. 8, in the structure of the type that the waterproof cap 2 is always forced toward the closing of the charging connector 1 by torsion spring 5, when charging is completed and a charging plug is then removed from the charging connector 1, the waterproof cap 2 is closed automatically. Therefore, there is no possibility that the operator forgets to close the waterproof cap 2.
However, in the charging operation, the operator must open the waterproof cap 2 with one hand to keep the cap in an opened state, while holding a charging plug with the other hand and fitting it with the charging connector 1. This requires operations to be performed clumsily with both hands. Also, in the waterproof cap 2 of this type, if the waterproof cap 2 and charging connector 1 are tightly fitted with each other for perfect waterproofing and dustproofing, then there arises a condition in which the waterproof cap 2 cannot be closed completely by the force of the torsion spring 5. It can also be expected that the force of the torsion spring 5 would be greatly increased. However, an extreme increase in the force reduces the operator's ability to open the waterproof cap 2.
As described above, in the structure shown in FIG. 8, because the fitting between the charging connector 1 and waterproof cap 2 must be relatively loose, the inherent function of the waterproof cap 2 cannot be performed fully, resulting in a structural problem.